Altcoins are dropping too, against BTC and USD. Even the only worthwhile ones, LTC and NMC, have tanked.

Altcoins have been easier to mine and more profitable for quite a while now, IIRC.

Bitcoin price is dropping because investors aren't very confident; a few huge dumps in low volume is all it took to get people scared, and we've never spent any considerable length of time testing $100 or even anything between $50 and where we are now.

Fasten your seatbelts, don't get caught in any bulltraps or beartraps!